Sources and Volume

Accelerator-Produced Materials

Accelerator-produced radioactive waste is produced during the operation of atomic particle accelerators for medical, research, or industrial purposes. The accelerators use magnetic fields to move atomic particles at higher and higher speeds before crashing into a preselected target. This reaction produces desired radioactive materials in metallic targets or kills cancer cells where a cancer tumor is the target. The radioactivity contained in the waste from accelerators is generally short-lived, less than one year. The waste may be stored at laboratories or production facilities until it is no longer radioactive. An extremely small fraction of the waste may retain some longer-lived radioactivity with half lives greater than one year. There are no firm estimates of the amount of this type of radioactive waste; however, it is generally accepted that the volume is extremely small compared to the other wastes discussed.

Naturally Occurring Radioactive Materials (NORM)

Naturally occurring radioactive materials (NORM) generally contain radionuclides found in nature. Once NORM becomes concentrated through human activity, such as mineral extraction, it can become a radioactive waste. There are two types of naturally occurring radioactive waste: discrete and diffuse. The first, discrete NORM, has a relatively high radioactivity concentration in a very small volume, such as a radium source used in medical procedures. Estimates of the volumes of discrete NORM waste are imprecise, and the EPA is conducting studies to provide a more accurate assessment of how much of this waste requires attention. Because of its relatively high concentration of radioactivity, this type of waste poses a direct radiation exposure hazard.

The second type, diffuse NORM, has a much lower concentration of radioactivity, but a high volume of waste. This type of waste poses a different type of disposal problem because of its high volume. The following are six sources of such naturally occurring radioactive materials.

Included for each category is an estimate of the volume that would accumulate over a 20-year period based on today's technology and production levels. It should be noted, however, that the level of radioactivity varies widely among these wastes.

Metal Mining & Processing Waste-20 billion metric tons.*

Coal Ash-1.7 billion metric tons

Phosphate Waste-800 million metric tons*

Uranium Mining Overburden-740 million metric tons

Oil and Gas Production Wastes-13 million metric tons*

Water Treatment Residues million metric tons*

*(Note that these categories may contain high-concentration radioactive components.)

Diffuse NORM may pose a health hazard because of its many uses. For example, though most metal-mining waste is stored near where it is generated, small amounts have been used as construction backfill and road building materials. It is also used in concrete and wallboard.

Coal ash is primarily used as an additive in concrete and as backfill.

Phosphate waste (slag) from the processing of elemental phosphorous has been used in construction and in paving.

Uranium mining waste is the soil and rock that is removed during surface or underground uranium mining. This waste is sometimes used to backfill mined-out areas and to construct roads around the mining site.

Oil and gas production may produce radioactive pipe scale (a residue left in pipes from drilling oil wells) and sludge that leave sites and equipment contaminated. Some radiation contaminated piping has been used by schools and other organizations for playground equipment, welding material, and fencing.

Radiation-contaminated water treatment residue accumulates when radioactive material is filtered out of drinking water during the purifying process. This waste may be disposed of in landfills or lagoons. It may also be used in agriculture as a soil conditioner.

There is increasing evidence that improper use or disposal of such naturally-occurring radioactive materials can result in significant contamination of the environment and radiation exposure. This can adversely affect the health of those occupationally exposed, as well as the public in general.

Disposal Issues

There are currently no federal regulations covering disposal of NARM with high radioactivity concentrations. Few states have regulations, and those regulations are inconsistent. The EPA has initiated studies to more accurately characterize the radiological hazards posed by NARM.

For More Information

The safe disposal of radioactive waste is a very important issue today. Radioactive waste disposal standards have changed substantially with improved technology and evolving environmental protection considerations. Regulatory programs and standards continue to change, so if you would like more information on the disposal of radioactive waste, write to: